Fix dependabot.yml formatting (#41979)

.github/dependabot.yml

@@ -13,15 +13,15 @@ updates:
       include: scope
     labels:
       - area-infrastructure
-   - package-ecosystem: "github-actions"
-     directory: "/"
-     schedule:
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
       # Weekly interval opens PRs on Monday.
       interval: "weekly"
-     commit-message:
-       prefix: "[main] "
-       include: scope
-     labels:
+    commit-message:
+      prefix: "[main] "
+      include: scope
+    labels:
       - area-infrastructure
 
   # Keep submodules up to date in 'release/*' branches. (Unfortunately Dependabot security PRs can't target these.)